Machine for shearing metal sheets.



G. B. JOHNSON.

MACHINE FOR SHEARING METAL SHEETS.

APPLIUATION I'ILED DEO. 30.1908.

Patented Nov. 23, 1909.

G. B. JOHNSON. MACHINE FOR SHEARING METAL SHEETS.

APPLIOATION I'ILED DEO. 30,1908.

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Patented Nov. 23, 1909 8 SEEETS-SHEET 2.

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V G. B. JOHNSON.

MAGHINE FOR SHEARING METAL sHEETs.

APPLIOATION FILED DEO. 30, 1908. 941, 1 99, Patented Nov. 23, 1909.

8 SHEETS-SHEET 3.

W/T/VELTJEL? G. B. JOHNSON.

MACHINE FOB SHEABING METAL SHEETS.

ArPLIoATIoN HLED nEo..so,19oa`.

' 941,199. Patented Nov. 23, 1909.

8 SEEETS-SHEET 4..

G. B. JOHNSON. MACHINE POR SHEAEING METAL sHEETs.

APPLIGATION FILED DEC. 30, 1908.

Patented Nov. 23, 1909. 8 SHEETS-SHEBT 5.

G. B. JOHNSON.

MACHINE FOR SHEARING METAL SHEETS.

ArPLIoATIoN HLED Dna. 30.1908.

941, 1 99. Patented Nov. 23, 1909. 8 sHEETS-SHEET 6.

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MACHINE FOR SHEARING METAL SHEETS.

ABPLIOATION FILED DEO. 30.1908.

941,199. Patente N0v.23,19o9.

Fig 12 8 SHEETS-SHEET 7.

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G. B. JOHNSON. MACHINE POR SHEfiRING METAL SHEETS. APPLIOATION HLED DEO.30,1908.

941 1 99. Patented Nov. 23, 1909.

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UNITED STATES PATENT OFFICE.

GODFREY BENINGTON JOHNSON, OF LONDON, ENGLAND.

MACHINE FOR SHEARING METAL SHEETS.

To all whom it ma/y concern:

Be it known that I, GonrRnY BENINGTON JOHNSON, a subject of the King ofGreat Britain, and resident of 8 Victoria street, in the city ofTWestminster, London, England, engineer, have invented an ImprovedMachine for Shearing lvletal Sheets, of which the following is aspecification.

This invention relates to an improved construction of shearing machinewhich is designed to facilitate, and reduce the manual labor incidentalto, the accurate shearing of metal sheets to a rectangular form, theprincipal object of the invention being to overcome the difficulties atpresent experienced in connection with such Operations when performed bya single shearing cutter to which the edges of the sheet aresuccessively presented, and more especially when it is required tosimultaneously cut a number of roofing sheets in the pack as the latteris delivered from the rolling mill.

The shearing machine of the present invention comprises a main knifehaving a length suflicient to cut, at a single stroke, the long edge ofthe longest sheet with which the machine is designed to deal, this knifebeing double-edged so as to be adapted to coact simultaneously with bothmembers of a pair of bed-cutters forming the opposed lateral edges of apair of similar tables disposed in one horizontal plane at therespective sides of the knife.

The machine also comprises two pairs of what may be termed auXiliaryknives whose function is to cut the ends of the sheet or pack, each pairof auxiliary knives` being arranged at one end of the main knife and themembers of each pair being mounted in alinement with one another so asto operate at right angles to and at opposite sides of, the main knife,in conjunction with bedcutters forming the corresponding end edges ofthe respective tables. Each of the auxiliary knives is of a lengthsufficient to cut, at a single stroke, the short edge of the widestsheet with which the machine is designed to deal.

In connection with either or both of the tables, stops are provided inrows parallel to the main knives and at distances therefrom and from theauxiliary knives corresponding to various standard widths and lengths ofsheet, these stops, which serve as guides for the work during thecutting oper- Specificaton of Letters Batent.

Application filed. December 30, 1908.

Patented Nov. 23, 1909.

Serial No. 470,017.

ation, being capable of being projected above or retracted flush withthe surface of the table according as they are or are not required to bein operation.

In the accompanying drawings Figure 1 is a plan view of a machineconstructed according to the present invention. Figs. 2 and 3 arerespectively a side and an end elevation of the same. Fig. 4 is acentral vertical transverse section of the machine. Fig. 5 is alongitudinal sectional elevation of the clutch mechanism for arrestingthe knives. Fig. 6 is an outside end elevation of the same, and Fig. 7is a face view of the clutch. Fig. 8 is an end elevation and Fig. 9 is aplan view of the cam mechanism for throwing the knife-arresting clutchinto and out of operation. Figs. 5 to 9 are drawn to a larger scale.Figs. 10, 11, 12, 13 and 14 are diagrammatic plan views illustrating thepreferred method of using the machine to cut a pack of roofing sheets;while Fig. 15 is a corresponding view showing the same pack aftershearing, the original form of the pack being indicated by dotted lines.

Similar reference letters and numerals denote corresponding partsthroughout the drawings.

The main knife comprises a holder A carrying at the lower edges of itsopposite faces a pair of blades A1, A2 (Fig. LL) adapted to coactsimultaneously with bed-cutters bl, 62 which constitute the opposedlateral edges of a pair of similar tables B1, B2 extending in onehorizontal plane at the sides of the knife. The end edges cl, 02 and(ll, (22 of the respective tables B1 and B2 are formed as bed-cutterswith which the auxiliary knives C1, C2 and D1, D2 coact, the knives C1,D1 extending in alinement with one another Aon opposite sides at one endof the main knife and those C2, D2 similarly at the other end thereof.

The main knife is of the guillotine type, the opposite end of its holderA being fitted to reciprocate vertically in guides as at 11 in the endframes 12 of the machine, and being provided with gudgeons 13 coupled byconnecting rods 141 to cranks 15 on a pair of horizontal crank-shafts 16extending in alinement with one another at opposite ends of the machine,and in the same vertical plane as that in which the main knifereciprocates. The cranks 15 are of equal throw and are adjusted inalinement with one another, the shafts 16 being also rotated at equalspeed, so that the cutting edges of the blades A1, A2 which are set atthe usual cutting angle with reference to the bed-cutters bl, 62,maintain their proper inclination to the bed-cutters throughout theentire stroke of the knife.

The auXiliary knives C1, C2; D1, D2 are of the scissor type and are soarranged as to open away from the main knife A, each knife constitutingone arm of a bell-Crank lever pivoted to the end frame 12 of the machineat c or cl as the case may be, while the other arm C or D of the leverextends downward and is coupled by a connecting rod 17 to the crank 15at the corresponding end of the machine. Each crank 15 consequentlyactuates (through three separate connecting rods) not only one end ofthe main knife, but also the two auxiliary knives at the same end of themachine, all the knives working together and performing one completecutting and return stroke for each revolution of the Crank-shaft 16, aswill be understood from Fig. 3.

The two crank-sliafts 16 (which rotate at a relatively low velocity) aredriven at each end from a single shaft 18 extending parallel to both,from end to end of the machine by means of a spur wheel mounted on saidsha ft engaging a large spur wheel mounted on a second aXis, said secondaxis carrying a smaller spur wheel engaging the spur wheel 21 attachedto the Crank shaft 16, the main or driving shaft 18 being rotatedcontinuously at a relatively high velocity from any convenient source ofpower, preferably through fast and loose pulleys as at 19 on the shaft.Since it is necessary at times to arrest the main knife when at thehighest point in its stroke, in order to permit of the work being passedfrom one table to the other beneath said knife as hereafter described,means are preferably provided for simultaneouslv disconnecting, at will,both Crank-shafts 16 from the main shaft 18 and for concurrentlypreventing rotation of these crankshafts when they attain the highestpoint in their throw; the consequent arrest of the cranks resulting inthe arrest of all the knives in the position indicated in Fig. 3. Thepreferred arrangement for effecting this is as follows.

Each Crank-shaft 16 carries a spur-wheel 21 which gears constantly witha pinion 22 fast on a Crank-shaft 20 driven from the main shaft 18, thewheel 21 being adapted to turn loosely (but without longitudinalmovement) upon the Crank-shaft and being provided at the outer end ofits hub 23 with one member 24 of a dog-clutch whereof the other member25 is on a clutch-body 26 splined upon the shaft 16. The dog-clutch issingle-toothed or otherwise so formed as to be capable of being throwninto gear only when its members 24 and 25 occupyone definite angularposition relatively to one another; this position corresponding to thatpoint in the revolution of the Crank-shaft when the crank 15 is at thehighest point in its throw.

In order to enable the clutches appertaining to the two crank-shafts 16to be operated simultaneously, each clutch-body 26 is engaged by al fork27 upon (or moving as one with) a lever 28 fulcrumed as at 29 andcontrolled by a helical cam 30, the cams appertaining to the twoclutches having convolutions which wind in opposite directions, andbeing fast on opposite 'ends of a rocking shaft 31 which extends fromend to end of the machine parallel to the main shaft 18. At each end,the rocking shaft 31 is provided with. a. hand-lever 32 by means ofwhich it may be partially rotated between limits (determined by stops33, 341) corresponding to the throw of the cams 30 and the movement ofthe clutch-bodies 26, each hand-lever 32 carrying a counterweight 35sufficient to retain the rocking shaft (together with. all thepartscontrolled thereby) iii that one of its two extreme angularpositions to which it may be thus brought.

i It being necessary that both crank-shafts 16, on being simultaneouslydisconnected from the main shaft 18, should (as already stated) also beinstantly arrested, each clutch-body 26 is provided, at the end oppositeto the clutch-mcmber 25, with a recess 36 which, on the cranks 15attaining the highest point in their throw, is engaged by a stud 37projecting from a stationary bearing 38 for the Crank-shaft, the recess36 being preferably in the form of a segmental slot slightly longer thanthe diameter of the stud 37 so as to allow time for the movement of theclutch-body lengthwise of the shaft on which it is splined. As it wouldbe inconvenient for the attendant to be coinpelled to remain on watch soas to be in readiness to operate either of the hand-levers 32, in thedirection to disconnect the crankshafts 16 from the main shaft 18, onlyat the exact moment when the recess 36 comes into registration with thestud 37, the latter is mounted to slide in a socket 39 parallel to theCrank-shaft 16, and is normally caused by a spring A10 to project fromthe face of the hearing 38 as shown in Fig. 5. The opposed face 41 ofthe clutch-body 26, wherein the recess 36 is formed, is made flat, sothat if the hand-lever 32 be operated to move the clutch-body 26 towardthe hearing 38 while the recess 36 and -stud 37 are out of registrationWith one another, the stud, being encountered by the flat face 11 of theclutchbody, will be forced back into its socket 39 against the pressureof the spring 10 until, on the recess coming opposite to the stud, thelatter will be shot outward by the spring into engagement with therecess and the clutch-body, together with the crank-shaft 16 whereon itis splined and all the knives driven by said shaft, will be arrested inthe position indicated in Fig. 3.

Inasmuch as the weight and inertia of the knives and other partsconnected to and moving as one therewith is very considerable, it isadvisable to make provision for obviating any risk of the studs 37 beingshorn off or hent in consequence of the severe transverse strain thrownupon them by the arrest of the knives and attachedV parts. For thispurpose the hearing 38 may, as shown, he itself mounted to rotatethrough a small angle in a secondary or outer hearing 42 which is fixed,the angular movement of the inner hearing 38 relatively to the outerbearing 42 (under the impulse communicated to the former from the knivesetc. through the stud 37) being limited by an elastc resistance adapted,after absorbing the inertia of the moving parts, to return them to aposition corresponding to the highest point in the throw of the cranks15 and main knife A. In the arrangement illustrated, the inner hearing38 is provided with an arm 43 between which and an anvil-hlock 44(carried by the fixed Outer hearing 42) a strong buffer-spring 45 isinterposed, this spring being constantly under compression so as tonormally retain the arm 43 in contact with a stop 46 serving todetermine the normal angular position of the hearing itself andtherefore'of the stud 37.

Each blade of the main knife is provided with an automatically actingspring-pressed clamp for holding the work firmly in position upon thetable during the :actual shearing operation. These clamps, which areindicated at A1, 2X, respectively, may be of any Ordinary or convenientconstruction whereby they are adapted to remain in aetion from justbefore the commencement to just after the completion of the cut, and t0he lifted at other times suffieiently above the table to permit of thework being slipped heneath the respective knives. It Will therefore heunnecessary to further describe or refer to them. If desired,corresponding spring-pressed clamps may be provided in connection withthe auxiliary knives.

The shearing operation is commenced upon the first or roughing out tableB1, whereon the knives C1, C2 are used for performing the preliminarytriinming operation on the respective ends of single sheets, the knifeC2 alone requiring to be thus used in the case of a pack, in connectionWith which it is employed to cut off the rough short end opposite to theprincipal fold before the pack is presented to the main knife A. As thelong edges of a sheet or pack are usually approximately straight andparallel to one another, the one farthest from the main knife may beutilized as a guide in cutting the other when this latter long edge ispresented to the main knife A for the purpose of making the first longcut. Accordingly two pairs of stops H, H are provided on the table B1 ata distance from one another less than the shortest length of sheet, eachpair (in the example illustrated) comprising front and rear stops 62, 63whose distances from the face of the blade A1 of the main knife are tobe understood as corresponding respectively to the two standard widthsof roofing sheets usually produced. As is well known, these standardwidths usually difer from one another in this country by six inches.Each of these pairs of stops is formed by the upper end of acounterweighted levei` 64 mounted to swing about an axis heneath thelevel of the table, the axes of the two pairs H, H being in alinementwith one another and being (in the arrangement illustrated) formed by asingle rod 65 which serves in common for both stop-levers and extendsparallel to the main knife A. The levers (34 project upward throughslots 66 provided in the table at right angles to the main knife, eachslot being of such position and length that While the upper end of thestop-levei` is normally retained by its counterweight in contact withthe end of the slot farthest from the knife, so as to be incapahle ofbeing moved farther from the latter, the lever can be rocked toward theknife so as to yield and disappear heneath the surface of the table if,for example, the sheetor pack, in being fed toward the main knife, ispushed against the back of the stops. In each pair of these stops H, H,the one 62 nearest to the main knife A is formed by the correspondingedge of the stop-lever (34, the other stop (33 of the pair being formedby a step on the upper end of the lever in rear of and at a higher levelthan the stop 62, so that in cases where the sheet or pack to be cut isof the greater of the two standaix. widths above mentioned, its rearmargiu may rest, not on the table out on the lower step of the twostop-levers, the rear edge of the sheet or pack then butting, notagainst the front stops 62, but against the rear stops 63.

After the necessary Operations have been performed on the roughing outtable B1, the sheet or pack is passed heneath the main knife A on to thesizing and finishing table B2. The stops (denoted broadly by thereference letter E) for determining both the finished width and lengthof sheet to be cut on this table B2, are provided 011 the upper ends ofa series of counterweighted levers 47 (similar to the stop-levers 64already described) mounted to swing independently of one another about acommon axis 48 beneath the level of the table, this axis extendingparallel to the main knife and the levers projecting upward throughslots as at 49 extending at right angles thereto.

Each lever 47 has its upper end steppcd to constitute two independentstops 50 and 51, and is normally held by its counterweight against therear end of the slot 49 so that all the front stops 50 are normallypresented in a straight row parallel to the main knife and at a distancefrom the blade A2 (at that side of the main knife) equal to the minimumwidth of sheet to be cut, while all the rear stops 51 normally standabove the level of the first stops 50, and likewise in a straight row,at a distance from the same blade A2 equal to the maximum width ofsheet. That end of each slot 49 which is farthest from the knife is soplaced that the stop-lever which projects through it cannot be turnedabout the axis 48 in a direction to move the stops on the lever fartheraway from the knife blade A2 than the distance just mentioned; but eachslot extends to- Ward the knife a distance sufiicient to permt of thelever yieldng to pressure in that direction so far that the lever can beturned through an angle suflicient to carry both stops 50 and 51 beneaththe level of the table as indicated in dotted lines in Fig. 4.

For the purpose of determining the finished length of sheet which can becut, the distances separating the successive stoplevers 47 from theopposed face of the finishing auxiliary knife D2 are made equal to theprogressively increasing standard lengths of sheet; such increase, as iswell known, being in this country usually one foot. The method of usingthe stops E for determining the length of sheet to be cut will beexplained hereafter.

In addition to the above described stops E (Which may be called the mainer sizing stops), other stops (denoted broadly by the reference letterF) are provided on the table 2 for the purpose of guiding the sheets asthe latter are slid along the table, in a direction parallel to the mainknife A, toward and under either of the auxiliary knives D1 or D2. Thesesecondary or guide-stops F, which are placed at about twice the distanceof the sizing stops E from the main knife, are arranged in two doublepairs or sets, one toward each end of the table. Each set comprises onepair of front stops 52, 52, set on a line parallel to the main knife Aand at a distance from the back of the main stops E rather less than theminimum width of sheet to be cut, and a second pair 53, 53 directly inrear of the first pair 52, 52 and at a distance therefrom approximatelyequal to the distance between the sizing stops 50 and 51.. Thearrangement is such that all the front stops 52, at both ends of thetable, extend in a straight row parallel to the main knife A while allthe rear stops 53 similarly extend in a second row parallel to thefirst.

The front pair of stops 52 of the set F at each end of the table arenormally held raised above the surface of the table while the rear pair53 are depressed beneath or kept flush with said surface, means beingprovided whereby, on the actuation of a treadle, the relative levels ofthe two pairs will be reversed for a purpose hereafter explained. Thismay be efi'ected by forming each stop as a plug mounted to slideVertically through an aperture in the table, one stop 52 and 53 of eachpair resting on the corresponding ends of a Sway-bar 54 fast on arock-shaft 55 which is journaled in bearings beneath the table andserves for operating both pairs of a set of stops; A lever 57, also faston the rock-shaft 55, is coupled by a rod 58 to a treadle-lever 59fulcrumed at 60 and provided with a treadle 61 in some positionconvenient for the attendant so that, on the depression of the treadle,the pair of stops 52 will descend and the pair 53 will be raised intooperative position. The swaybars 54 may be retained in their normalangular position by means of a spring or Springs as indicated.

Each table B1 and B2 is preferably formed with a. gap or gaps openingout at the edge farthest from the main knife A, so as to enable theattendant at that side of the machine to gain access readily to thework, upon whatever part of the table it may be lying, the gap or gapsbeing however so arranged as to avoid interfering with the support whichthe table must under all circumstances afford to the work. In order thebetter` to insure this, each gap may be made capable of sub-division atwill by means of a folding leaf or leaves, each leaf extending into thecorresponding gap so as, by presenting normally an extension of thegencral surface of the table, to afford an intermediate support for thework When the latter is laid across the gap at that point, but beingcapable of being dropped so as to permit of the at-tendant moving freelyat a shorter distance from the knife or knives.

In the arrangement illustrated, each table has, in addition to smallergaps g between the pairs of stops F at each end of the table, a largecentral gap G of approximately T- shape which is normally divided intotwo portions by a leaf J hinged to the edge of the table as at 67 andcapable of being folcled downward out of the way when desired. For thispurpose each leaf J may be supported by means of toggle mechanismcomprising a lever 68 pivoted at 69 to the base of the machine and alink 70 pivoted to said lever at 71 and to the underside of the leaf at72, a handle being provided on the lever 68 as at 73 for manipulatingthe leaf. When the toggle is straightened out to support the leafrigidly in the raised position, the lever 68 is arrested by a sto 74.

Each table would be provided with the customary grooves or slots (notshown) for the accommodation of the usual claW-grabs employed inhandling the sheets or packs.

The preferred method of using the machine will be described withreference to Figs. 10 to 15 and is as follows. Let it be assumed that itis required to cut a pack P (Fig. 15) whose folded end (in the case of apack of four, the double-folded end) is denoted by Z, its opposite orrough end by WT, and its rough long sides by X and Y respectively. Thepack is first laid upon the table B1 with the straight fold Zapproximately parallel to the auxiliary knife C2; the pack is then slidbodily toward and beneath the opposite knife C1 (see Fig. 10) so thatthis knife, on descending, shall shear off the rough end VJapproximately parallel to the fold Z and at the greatest practicabledistance therefrom. The pack, having now two approximately parallelstraight ends w and e, is slid clear of the knife C1, and pushed overthe pairs of stops H (which yield to the pressure thus applied to themfrom behind) until that edge Y of the pack which is farthest from themain knife A drops over and rests in contact with either the rear stops63 or the front stops 62 according as the sheets to be cut are of themaximum or minimum standard width. In the example illustrated the sheetsare supposed to be of the maximum width, so that, when the long roughedge Y of the pack is in contact with the rear stops 63 of each pair Has shown in Fig. 11, the other long rough edge X will be in a positionto be shorn by the blade A1 of the main knife A which coacts with thebed-Cutter bl of the table B1. VVhen the main knife has performed itsshearing stroke, the first long cut edge x thus produced constitutes aguiding edge for all the succeeding operations. The main knife A is nowarrested at the highest point in its stroke, and the pack is thereuponslid through beneath this knife until the greater part of it rests uponthe table B2, the cut edge a: being either allowed to butt against thefirst or front stops 50 (of the sizing set E), or lifted over thesefirst stops so as to butt against the second or rear stops 51 (of thesame set), according as the pack is capable of producing sheets of theminimum or maximum width. In the example illustrated (see Fig. 12), itbeing assumed that sheets of the maximum width will be produced, therear stops 51 are shown as in use. The main knife A is thereupon allowedto descend, when its blade A2 (nearest the sizing stops E) will shearthe rough long side Y of the pack, forming a second long cut edge fz/truly parallel to, and at the desired distance from, the long cut edge walready shorn. The

pack is now drawn over the sizing stops E, and away from the main knifeA, in order that its ends may be trimmed. Assuming the cut edge w to benot quite truly at right angles to the long parallel edges m and y, thisshort edge w is first trued-up. For this purpose the long edge :v iscaused to butt against either the front or rear pair 52 or 53 of thatset of guide-stops F which appertain to the auxiliary knife D1 at thecorresponding end of the machine, according as it may be found mostconvenient in view of the width of the pack. In the example illustrated(see Fig. 13) it being assumed that the pack has been cut to the maximumwidth, the rear stops 53 are shown as in use, the treadle 61 whichserves to withdraw the front stops 52 of the same set and raise thesestops 53 to operative position being depressed for this purpose. At thesame time, as many of the sizing stops E as may be necessary are thrustforward out of the way to make room for the pack in its presentposition, as indicated, the sizing stops swinging freely for the purposeabout their common axis. Using the stops 53 as a guide, the pack is nowslid lengthwise toward and beneath the knife D1 just so far as may benecessary to trim the already cut edge w so that its entire length shallbe at right angles to both the long edges w and y. There remain now onlythe final Operations of determining the length of sheet to be producedfrom the pack, and of shearing the folded end Z so as both to bring thepack as a whole to this length, and also, simultaneously, to sever fromone another the various superposed sheets which thus far have beenunited by the fold. Now, as has been already explained, the distances ofthe respective sizing stops E from the finishing auxiliary knife D2 aremade equal to the several standard lengths of sheet to be cut. Hence, inorder to determine the finished length of the sheet, it is onlynecessary to slide the pack lengthwise toward the knife D2 (still usingthe stops F as guides, and of course now bringing into play those at thecorresponding end of the table) until, as a first requirement, the packhas passed far enough beneath the knife DL to insure the fold Z beingcompletely shorn off on the descent of the knife (this being the minimumrequirement as to distance) and, as a second requirement, to cause thealready trimmed end u of the pack to butt against the lateral face ofthat one of the sizing stops E which is the farthest from the knife D2that will permit of such complete severance at the fold Z beingeffected. Obviously those sizing stops E which intervene between the oneselected and the knife D2 must incanwhile be thrust forward toward themain knife A out of the way of the pack as indicated in Fig. 14. Theknife D2 may now be allowed to descend so as to shear off the fold Z atz, when the entire operation will be coinplete, the Whole beingaccurately efected Without the necessity of either marking out, turningover, or sluing around the pack; manifest advantages of the greatestimportance. The finished and severed (but still superposed) sheets intoWhich the pack is thus divided may noW be removed from the machine.

It Will readily be seen that While the various Operations are proceedingas described on the table B2, the preliminary trimming of the rough endVV and first rough side X of a fresh pack on the table B1 may beefected.

The Waste cuttings from the main knife A fall through the space betweenthe bed-cutters bl and 122 and may be received on a trolley running uponrails in a pit or tunnel eXtending beneath and parallel to the mainknife, it being obvious that both the main shaft 18 and rocking shaft 31should be placed clear of the mouth of this pit.

If preferred, each table B1 and B2 may be used independently for cuttingseparate series of sheets or packs, an arrangement Which, however,obviously involves the Work being either turned over or slued aroundbetween the first and second long cuts in order that the long sides ofthe sheet or pack may be presented in succession to the same side of themain knife.

In some cases, as for example Where sufficient room is not available forthe installation of a duplex machine as above described, a single tableonly may be provided, the main knife in such case having only oneWorking edge and auxiliary knives being provided only at that side ofthe main knife at Which the table is placed.

Having now particularly described and ascertained the nature of the saidinvention and in What manner the same is to be performed, I declare thatWhat I claim is 1. A machine for shearing metal sheets to rectangularform Without the necessity of turning over or sluing around the Workbetween successive stages of the shearing operation, comprising adouble-edged main knife adapted to coact simultaneously With bothmembers of a pair of bed-cutters forming the opposed lateral edges of apair of tables disposed in one horizontal plane at opposite sides ofsaid knife; two pairs of auxiliary knives each situated at one end ofthe main knife, the members' of each pair being arranged on oppositesides of and at right angles to the main knife so as to be adapted tocoact With bed-cutters forming the corresponding end edges of therespective tables; and stops adapted to serve as guides for the Work onthe tables, disposed in roWs parallel to the main knife and at distancestherefrom and from the auxiliary knives corresponding to various Widthsand lengths of sheet to be produced, substantially as set forth.

2. In a machine for shearing metal sheets to rectangular form Withoutthe necessity of turning over or sluing around the Work betweensuccessive stages of the shearing operation, the combination of adoubleedged main knife adapted to co-act simultaneously With bothmembers of a vpair of bed cutters forming the opposed lateral edges of apair of tables disposed in a hor'- zontal plane at opposite ends of saidknife, tWo pairs of auxiliary knives each situated at one end of themain knife, themembers of each pair being arranged on opposite sides ofand at right angles to the main knife so as to be adapted to co-act Withbed cutters forming the corresponding end edges of the respectivetables, stops adapted to serve as guides for the Work on the tables,said stops being disposed in roWs parallel to the main knife and at adistance therefrom and from the auxiliary knives corresponding tovarious Widths and lengths of the sheet to be produced, and meansWhereby the roWs of stops may be brought alternately above the table. V

8. In a machine for shearing metal sheets to rectangular form Withoutthe necessity of turning over or sluing around the Work betweensuccessive stages of the shearing operation, the combination of adouble-edged main knife adapted to co-act simultaneously With bothmembers of a pair of bed cutters forming the opposed lateral edges of apair of tables disposed in one horizontal plane at opposite ends of saidknife, two pairs of auxiliary knives each situated at one end of themain knife the members of each pair being arranged on opposite sides ofand at right angles to the main knife so as to be adapted to co-act Withbed cutters forming the corresponding end edges of the respectivetables, stops adapted to serve as guides for the Work on the tables,disposed in roWs parallel to the main knife and at distances therefromand from the auXiliary knives corresponding to various Widths andlengths of sheet to be produced, and means for enabling each row ofstops to be alternately brought above the table, said means comprisin ga sWay bar Wherein said stops rest, a rockshaft secured to saidSway-bar, a lever fast on said rock-shaft, a rod coupled to said lever,and a treadle lever attached to said rod, substantially as set forth.

In a machine for shearing metal sheets to rectangular form Without thenecessity of turning over or sluing around the Work between successivestages of the shearing operation, the combination of a double-edged mainknife adapted to co-act simultaneously With both members of a pair ofbed cutters forming the opposed lateral edges of a pair of tablesdisposed in one horizontal plane at opposite ends of said knife, andmeans for enablinzg` said double-edged main knife to be arrestecl Whenat the highest point in its stroke, said means comprsing at each end ofsaid knife, a gudgeon attached to said knife, a connecting rod coupledto said gudgeon, a crank coupled to said connecting rod, a crank-shaftattached to said crank, a spur Wheel adapted to turn loosely on saidshaft, a female member of a single-toothed dog` clutch formng part ofand attached to said spur Wheel, a male member of said single tootheddog clutch adapted to engage said female part, said male member of saidsingletoothed dog-clutch splined upon said shaft, said male member ofsaid single-toothed dogclutch engaged by a fork, said fork attached to afulcrumed lever, said fulcrumed lever controlled by a helical cam, arocking shaft connected to said cam, a hand lever attached to saidrocking` shaft, a counterweight attached to said hand lever,substantially as set forth.

5. In a machine of the character described, the combination With atable, of knives arranged at three edges of the table and coacting Withsaid cdges, means for operating said knives, and stops adapted to serveas guides for the Work on the table, said stops being at a distance fromthe knves corresponding to the various Widths and lengths of the sheetto be produced.

6. In a machine of the character described, the combination With atable, of knives arranged at three edges of the table and coacting Withsaid edges, means for operating` the knives, movable stops serving asguides for the Work on the table and arranged in the table at a distancefrom the knives corresponding to the Various Widths and lengths of thesheet to be produced, and means Whereby the stops may be broughtalternately above the table top.

GODFREY BEN'INGTON JOHNSON.

VVitnesses:

GEORGE E. MINTERN, XVILLIAM G. E. DAVIES.

